Resilient mounting



4 Sheets-Sheet 1 Filed Nov. 26, 1948 3nnentor attorney Jan. 29, 1952 w. A. KEETCH RESILI'ENT MOUNTING 4 Sheets-Sheet 2 Filed Nov. 26, 1948 Zhwentox C(Hornegj Jan. 29, 1952 w. A. KEETCH RESILIENT MOUNTING '4 Sheets-Sheet 5 Filed Nov. 26, 1948 3nuentor Jan. 29, 1952 w. A. KEETCH 2,533,948

RESILIENT MOUNTING Filed Nov. 26, 1948 4 Sheets-$heet 4 lnnentor W QW (morneg Patented Jan. 29, 1952 RESILIENT MOUNTING William A. Keetch Erie, Pa., assignor to Lord Manufacturing Company, Erie, Pa., a corporation of Pennsylvania Application November 26, 1948, Serial No. 61,968

8 Claims.

Mounting systems have been proposed using hinged links having diiierent stiffness along and transverse to the length of the links for projecting the elastic center of a supported body to axes remote from the attaching points on a supported member. This invention is intended to improve the link type mounting system by a construction utilizing rubber sandwich mountings transverse to the link. In one form, the sandwich mountings are arranged on opposite sides of an annular member having trunnion bearings at its edges and the connection to the link is made through a stem extending through the annular member and fixed to the sandwich mountings at points spaced from the annular member. Among the advantages obtainable are uniform loading of the rubber, equal stiffness in both directions along the length of the link, and controlled snubbing in all directions. Further objects and advantages appear in the specification and claims.

In the drawing, Fig. 1 is a side elevation of a mounting for a gear box forming a speed reducing connection between an aircraft engine and propeller (not shown); Fig. 2 is an enlarged section through one of the mounting links; Fig. 3 is a side elevation, partly broken away, of one of the mounting links; and Fig. 4 is an exploded view of one of the mounting links.

In the drawing, the mountings are shown supporting a gear box I forming a speed reducing connection between an aircraft engine and propeller (not shown) carried by a mounting ring2 surrounding the torque axis of the gear box and rearward cf the center of gravity so that the gear box is supported and in overhung relation to the mounting ring. The gear box has the same vibration problems as a radial aircraft engine supported in overhung relation to the engine ring and the mountings for gear boxes and for aircraft engines are interchangeable. The gear box has a series of mounting pads 3 to which are fixed brackets 4 having spaced ears 5 carrying comprise anti-friction bearings Illa seated in oppositely facing sockets I01; and cooperating with studs Hlc integral with edges of the plate II. The

arrangement of the pads 3 and 8 is such that the links converge toward the torque axis I2 of the gear box providing a. virtual support in the region of the center of gravity.

In mounting systems of this type it is desirable that the stifiness of the link along its longitudinal axis be materially greater than the stiffness along a cross axis. In the present construction this stiffness ratio is obtained by sandwich mountings having annular bodies l3 of rubber or equivalent resilient material sandwiched between and bonded to the opposing faces l4, 15 of spaced metal plates I8, II. The metal plates ll have inturned flanges l8 seated in recesses IS on opposite sides of the annular plate II. The plates H; are seated on the link 1 and areclamped between a shoulder 20 on the link and a shoulder H on a nut 22 threaded on the end of the link. In the assembled position the link I, in efiect, has a stem 23 extending through an opening 24 at the center of the annular plate II and spaced from the side walls of the annular rubber bodies l3 so that upon relative motion of the annular plate ll transverse to the axis of the link, the rubber is free to yield in shear. Upon motion of the plate ll along the axis of the link the rubber is stressed in direct stress (compression or tension). The stiffness along the axis of the link is controlled by plates 25 embedded in the rubber parallel to the plates [6 and I"! which restrict bulging of the rubber under direct stress. Because the rubber bodies l3 are symmetrical the stifiness along the longitudinal axis of the link is the same in both directions. This result would not be obtained if the rubber on one side of the annular plate I I were shaped differently from the rubber on the other side of the plate.

In the particular construction illustrated where the axis of the trunnion bearing I0 is parallel to the axis of the hinge pin 6 and both axis are on the longitudinal axis of the link I, there is no cocking or tilting action in the rubber. Forces along the axis of the hinge pin 6 stress the rubber uniformly in shear parallel to the opposing faces [4 and I5 of the metal plates 16 and I1. Due to the absence of cooking or tilting the shear stress is uniform throughout the rubber. Couples about the axis of the hinge pin 6 cause a bodily swinging movement of the link with no stress in the rubber except that due to the negligible bearing friction. Since all force transverse to the longitudinal axis of the link can be resolved into forces acting along and couples about the axis of the hinge pin 6, it is apparent that no force transverse to the axis of the link can cause non-uniform loading of the rubber. If the trunnion bearing III were located ent. ma erial such a ing parallel sides 26 at ri ht angles to the trunnion axis and slightly spaced from flats 2,? on the stem 23. At each end of the flats 21 is a shoulder 28 which cooperates with the plate I! to positively limit movement/along the-"axis of 4 mountings on opposite faces of the annulus and surrounding the stem, each sandwich mounting having an end plate fixed to the stem and resilient material'such as rubber between the end plate and the adjacent face of the annulus.

4. In a resilient mounting, a pair of brackets for connection to supporting and supported members, an annulus carried in one bracket by trunnions at opposite edges of the annulus, a' stem hinged to the other bracket and extending through the annulus, a pair of sandwich mountings on opposite faces of the annulus and surrounding the stem, each sandwich mounting hav-' ing an end plate. fixed to the stem and resilient the link. Surrounding the stem 23 betweenthe shoulders 28 is an elongated snubbing ring as havi sru erflfl, b d to ts. ends n p atingwith the end surfaces iii of the opening 2% to yieldably snub movementalong' thefaxis of thet'runnion bearing In; a Fig. 2. the mountin is in the: unloaded positibn. Under load the rubb er bumpers as would normally be midway betweentlie' end surfaces else that the bumpers would lie equally effective to snub extrerne movementin eitherdirection along the Quill??? 33 I V 'lghe brackets are made in two pieces, each comprising an arm SZfhaving at one end one of the trunnion bearings Illa. and at the other'end a boss 13;: fitting'in a socket 34 in thepad 8. The conneqt enio. l s-meanin s r n s e a lt =1 te eee dini he b s '3 when be ts ar t htwai ir ees i he bracket 9 a e brq s t into enga s it' h. g, faces 3] on thepad 8" p idl ng a stable connecext nsions 8 which r s 1. a a nita 1 m t clearancein the bolted mmoda te variationsin the e it b a c n tru ti n die el-mails else dvan age i meditatin assume. an disas 'smblr 17', he mount n s" i Lc me In resil entme s. n. annu s havi ,trs nic s atepnes ie fedst aP i 0i sendw'ih y l gnpe i e aces the .s. ndf e s and re ru be b tw n t e ri pl and the. a jac nt ace o h annu san a stem. extendin thrqush h annulus and fir t the. end at s mou tings es e iy annu us. each. neg-. 1

resilient-mo ntin annulus. having.

trunniqns t. posite. dg s... 2 a r f. sendwis m unt n s. res ecti el op osite. as sqi. the

ann lu a h. om r in an. e d. plate an mail:

ientmateri l uches ubbe b e ntl e en p e a the ad acent a f. e n lu te end n t r ug he and. to the end plates, and asleeve of resilient mate;-

rial on e stem ooperetinaw h. he annul s to limit movement of the tem. qward mea nulus.

3., In. a resi ie ountin apair r c ets for connection to supporting and supported members, an. annulus carried inone bracket t nni nsj a pposit es of t nulu a st m. hins d q h qtlienbrecket an x en throu h. the and. a can. o sandw ch th pairs "of arms 4;

material suchas rubber between the end plate torque axis and converging toward" each other, a

pair of brackets for connection respectively to the engine and its support, a link comprising an annulus generally tangent to a sphere centered on the torque axis and hinged in one bracket by trunnions at opposite edges of the annulus, a stem hinged in the other bracket and extend ing through the annulus, and a pair of sandwich mountings on opposite faces of the annulus and surrounding the stem, each sandwich rriounting having an end plate fixed to the stern and resilient material such as rubber'between the end plate and the adjacent face of the annulus.

6. In a resilient mountingsupporting and sup.- ported members, an annulus hinged to one memher, a stem hinged to the other member and extending through theannulus, and a pair-of sandwich mountings on opposite faces of the annulus and surrounding the stem. each sandwich mounting havingan end plate fixed to the stern and resilient material such as rubber between the end plate and the adjacent face of they annulus.

7 In a resilient mounting, supporting and supported members, an annulus hinged to one nernher for swinging mowment on. a fixed axi s, a stem hinged to the other member for swinging movement on an axis parallel to said fixed and extending through thea nnulus, and; a pair of sandwich mountings on opposite facesjof "the annulus and surroundingthe stern, each sandwich mounting having an end plate fixed tothe stem and resilient material such as rubber'bet en t end lat a d th -ad a nt a o the annulus REFERENCES CITED The. following references; are. of record in the file of this patent:

Name Date 2,175,999 Taylor Oct. 10; 1939 

